• Korean Journal of Materials Research
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• v.21 no.12
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• pp.679-684
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• 2011

One of the trace constituents included in cement clinker, chromium, has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects the human body negatively. The purpose of the present study was to investigate leaching properties of water-soluble hexavalent chromium by different manufacturing conditions of cement clinker. Raw materials were prepared to add different $SiO_2$, $Al_2O_3$ and $Fe_2O_3$ sources. After the raw materials, such as limestone, sand and clay, iron ore was pulverized and mixed, and the raw meal was burnt at $1450^{\circ}C$ in a furnace with an oxidizing atmosphere. Leaching of soluble hexavalent chromium showed a tendency to decrease with an increasing LSF and IM. However, leaching of soluble hexavalent chromium increased with an increasing S.M. Alkali contents of iron source minerals is closely related to the leaching properties of soluble hexavalent chromium. Green sludge has the highest content of alkali added; leaching of water-soluble hexavalent chromium was mostly high. In order to reduce the water-soluble hexavalent chromium in cement, reducing the alkali content in raw materials is important.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.67-70
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• 1998

In order to understand the influence of ferroxidase center on the protein assembly and solubility of tadpole ferrin, three mutant plasmids, pTH58K, pTH61G, and pTHKG were constructed with the aid of site-directed mutagenesis and mutant proteins were produced in Eshcerichia coli. Mutant ferritin H-subunits produced by the cells carrying plasmids pTH58K and pTHKG were active soluble proteins, whereas the mutant obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence of sorbitol and betaine. Especially, the cells carrying pTH61G together with the plasmid pGroESL harboring the molecular chaperone genes produced soluble ferritin. The mutant ferritin H-subunits were all assembled into ferritin-like holoproteins. These mutant ferritns were capable of forming stable iron cores, which means the mutants are able to accumulate iron with such modified ferroxidase sites. Further functional analysis was also made on the individual amino acid residues of ferroxidase center.

• Clinical and Experimental Pediatrics
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• v.58 no.1
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• pp.15-19
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• 2015

Purpose: Soluble transferrin receptor (sTfR) is a truncated extracellular form of the membrane transferrin receptor produced by proteolysis. Concentrations of serum sTfR are related to iron status and erythropoiesis in the body. We investigated whether serum sTfR levels can aid in diagnosis and treatment of iron deficiency anemia (IDA) in children. Methods: Ninety-eight patients with IDA were enrolled and were classified according to age at diagnosis. Group 1 comprised 78 children, aged 6-59 months, and group 2 comprised 20 adolescents, aged 12-16 years. Results: In group 1, patients' serum sTfR levels correlated negatively with mean corpuscular volume; hemoglobin (Hb), ferritin, and serum iron levels; and transferrin saturation and positively with total iron binding capacity (TIBC) and red cell distribution width. In group 2, patients' serum sTfR levels did not correlate with ferritin levels and TIBC, but had a significant relationship with other iron indices. Hb and serum sTfR levels had a significant inverse relationship in both groups; however, in group 1, there was no correlation between Hb and serum ferritin levels. In 30 patients of group 1, serum sTfR levels were significantly decreased with an increase in Hb levels after iron supplementation for 1 month. Conclusion: Serum sTfR levels significantly correlated with other diagnostic iron parameters of IDA and inversely correlated with an increase in Hb levels following iron supplementation. Therefore, serum sTfR levels can be a useful marker for the diagnosis and treatment of IDA in children.

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.717-724
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• 2000

A number of epidemiological studies has indicated lifestyles including dietary habits are closely related to the development of certain forms of cancer. These findings have led several investigators to identify the ways in which these factors mdulate the risk of cancer. Seaweeds are rich sources of non-digestible polysaccharides which possibly posses physiological functions. In vitro studies showed several components in seaweeds inhibit tumor cell growth and mutagenicity of known food mutagens. On the other hand non-digestible polysaccharides of different food sources negatively affect mineral nutrition by decreasing mineral absorption. The objectives of this study was to investigate the effect of major seaweed intake on azoxymethane(AOM) - induced DNA damage a known cancer initiation step and on apparent absorption of calcium and iron. To accomplish these objectives twenty five ICR mice were divided into five groups and fed one of the following diets for 10 days : control diet d, diet containing 10% water-soluble fraction of seamustard or seatangle diet containing 10% water-insoluble fraction of seamustard or seatangle. AOM was injected 6 hours before sacrifice and N7-methylated guanines from the colonic DNA were quantified using a gas chromatography -mass spectroscopy. Fecal samples were collected on days 4 and 8. Caclium and iron contents of the diets and feces were analyzed using an atomic absorption spectrophotometry to determine the apparent absorption of these minerals. Results are as follows. AOM-induced guanine methylation of colon was decreased in animals fed diets containing water-soluble fractions of seamustard or seatangle compared to those in animals fed control diet although only the seatnagle fed group showed statistically significant effect. Apparent calcium absorption was significantly reduced in animals fed diets containing water-insoluble fractions of seaweeds. Iron absorption was significantly decreased and negatively balanced in animals fed diets containing water-insoluble fractions of both seaweeds, and water-soluble fraction of seatangle. In conclusion, seamustard and seatangle intakes may effectively prevent colon tumorigenesis by reducing a carcinogen-induced DNA damages, and more mechanistic studies on possible role of seaweeds on carcinogenesis are required. Also, adverse effects of seaweed diets cintaming a large amount of polysaccharides on mineral nutrition should be carefully monitored.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.705-709
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• 1999

To evaluate iron bioavailability in iron fortified milk, in vitro and in vivo method were used. Low molecular weight components(ILC) from milk was isolated and iron was added, then soluble iron from ILC iron complex was determined. Each iron sources and extrinsically labelled with FeCl3 was used for measuring absorption rate of iron from ILC radiolabelled iron complexes as radioiron absorption into the blood one hour after injection into ligated duodenal loops of iron deficient rats. Iron absorption rate was in the order of ferrous lactate(25.56%)$\geq$ferric citrate(24.71%)$\geq$ferrous sulfate(19.67%) when 100ppm iron was used. In separate experiments, iron fortified milks with each iron sources were gavaged into iron deficient rats. When 25ppm iron was added to milk, the order of iron absorption was ferrous sulfate(12.52%)>ferrous lactate(8.07%)>ferric citrate(6.52%) (p<0.05). When 100ppm iron was added to milk, absorption rate was decreased compared to the treatments with added 25ppm of iron. Absorption rate of ferrous sulfate(5.34%) from milk added 100ppm iron was highly lowered, but ferric citrate(6.45%) was not significantly changed. The absorption rate of ferrous lactate(5.82%) was 70% of 25ppm iron added milk.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.282-288
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• 1985

This experiment was conducted to investigate the changing patterns of the available elements by the control of lime addition amount and temperature in Acid Sulfate Soils under the submerged condition. The results obtained were summarized as follows: 1. pH and contents of available phosphate, soluble silicate, $NH_4-N$, and exchangeable iron in soils were decreased but exchangeable aluminium and manganese, and water soluble sulfur in soils increased after submergence. 2. Lime treatment increased pH, available phosphate, soluble silicate, $NH_4-N$, and water soluble sulfur, but that decreased exchangeable aluminium, iron, and manganese in soils. 3. Treatment with 12me/100gr of Ca as $CaCO_3$, showed the marked effect in increasing the exchangeable aluminium and iron, and increasing pH value to about 6.5 as well as available phosphate and $NH_4-N$. 4. Increases in available phosphate, $NH_4-N$, and exchangeable iron with aging of the soil flooded and lime treated were higher at $35^{\circ}C$ than those at $25^{\circ}C$. 5. Throughout submerged period a significant positive correlation was observed between pH and soluble silicate while the pH has negative correlation with exchangeable elements such as aluminium, iron, and manganese etc.

• 한국해양학회지
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• v.12 no.1
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• pp.48-53
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• 1977

Various types of iron were determined in 5 meters interval from surface to bottom layers in Yeongil Bay water of Korea, late October 1973. The contents of every type of iron decreased outward from the inner part to the entrance of the bay. But there was not any difference in iron contents among the water masses. Particulate iron and ferric iron were lower in the entrance and central parts than in the inner parts of the bay. It seemed to be caused by turbidity. The concentration of soluble iron showed higher value at the area of entrance of harbour than those of any other stations. It suggests that there may be the origin of pollutants.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.398-400
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• 1995

Selective oxidation of cyclohexane in acetone solution has been studied using iron catalysts with hydrogen peroxide in-situ produced by palladium catalyst. Iron tetraphenylporphyrin chloride shows the highest activity among the tested chlorides and porphyrin complexes of some metals of the first transiton series. Iron chloride and iron tetraphenylporphyrin chloride were supported on four kinds of 4-vinylpyridine copolymer with styrene or divinyl-benzene. Nitrogen 1s photoelectron spectra give the evidence that pyridyl nitrogens of the 4-vinyl pyridine copolymer act as ligands to bind iron species. The copolymer with styrene is the most efficient support for the binding because its solubility in catalyst preparation solvent (methylene chloride) gives the pyridyl group advantage to contact with the iron catalysts. However, better catalytic activity per iron atom could be obtained with a rigid crosslinked polymer due to active site isolation.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.861-866
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• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.